1949 U.S. National Championships – Women's singles
# 1949 U.S. National Championships – Women's singles

Second-seeded Margaret Osborne duPont defeated Doris Hart 6–4, 6–1 in the final to win the women's singles tennis title at the 1949 U.S. National Championships.

## Seeds

The tournament used two lists of seven players for seeding the women's singles event; one for U.S. players and one for foreign players. Margaret Osborne duPont is the champion; others show in brackets the round in which they were eliminated.

## Draw

### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* r = Retired

### Final eight

| Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Finals | Finals | Finals | Finals |
| - | - | - | - | - | - | - | - | - | - | - | - | - |
| 1 | Louise Brough | 6 | 2 | 6 | | | | | | | | |
| 7 | Beverly Baker | 1 | 6 | 2 | | | | | | | | |
| 7 | Beverly Baker | 1 | 6 | 2 | 1 | Louise Brough | 5 | 1 | | | | |
| | | | | | 3 | Doris Hart | 7 | 6 | | | | |
| 3 | Doris Hart | 6 | 6 | | 3 | Doris Hart | 7 | 6 | | | | |
| | Barbara Scofield | 2 | 0 | | | | | | | | | |
| | Barbara Scofield | 2 | 0 | | | | | | 3 | Doris Hart | 4 | 1 |
| | | | | | | | | | 2 | Margaret Osborne duPont | 6 | 6 |
| 2 | Margaret Osborne duPont | 6 | 10 | | | | | | | | | | 2 | Margaret Osborne duPont | 6 | 6 |
| 6 | Pat Canning Todd | 3 | 8 | | | | | | | | | |
| 6 | Pat Canning Todd | 3 | 8 | | 2 | Margaret Osborne duPont | 6 | 6 | | | | |
| | | | | | (1) | Betty Hilton | 2 | 3 | | | | |
| (1) | Betty Hilton | 6 | 6 | | (1) | Betty Hilton | 2 | 3 | | | | |
| | Helen Perez | 2 | 3 | | | | | | | | | |
